A person travels by car from one city to another with different constant speeds between pairs of cities. She drives for 40.0 min at 85.0 km/h, 12.0 min at 95 km/h, and 35.0 min at 30.0 km/h, and spends 35.0 min eating lunch and buying gas. Determine the average speed for the trip?
34.9+12.8+50.4+18.8=116.9/60=19.483hrs
distance
76.5+96.7+37.7=210.9
210.9km/1.1083hrs=190.2914km/h ??????
done it so many times am so confuse!!!
Read my previous answer
To determine the average speed for the trip, we need to find the total distance traveled and the total time taken for the entire trip.
First, let's calculate the total distance traveled. Given that the person traveled at different speeds for different durations, we can calculate the distance traveled during each leg of the trip.
The distance traveled during the first leg (40.0 min at 85.0 km/h) is:
Distance_1 = (Time_1/60) * Speed_1
= (40.0/60) * 85.0
= 56.67 km
The distance traveled during the second leg (12.0 min at 95 km/h) is:
Distance_2 = (Time_2/60) * Speed_2
= (12.0/60) * 95
= 19.0 km
The distance traveled during the third leg (35.0 min at 30.0 km/h) is:
Distance_3 = (Time_3/60) * Speed_3
= (35.0/60) * 30.0
= 17.5 km
Now, let's calculate the total distance:
Total Distance = Distance_1 + Distance_2 + Distance_3
= 56.67 + 19.0 + 17.5
= 93.17 km
Next, we need to calculate the total time taken for the entire trip. Given that the person also spent 35.0 min eating lunch and buying gas, we need to add this time to the time spent driving.
Total Time = Time_1 + Time_2 + Time_3 + Lunch and Gas Time
= 40.0 + 12.0 + 35.0 + 35.0
= 122.0 min
Now, let's convert the total time to hours:
Total Time in hours = Total Time / 60
= 122.0 / 60
= 2.0333 hrs (rounded to four decimal places)
Finally, to calculate the average speed, divide the total distance by the total time in hours:
Average Speed = Total Distance / Total Time in hours
= 93.17 km / 2.0333 hrs
= 45.81 km/h (rounded to two decimal places)
Therefore, the average speed for the trip is approximately 45.81 km/h.